Chapter Ii. the Common Elements, Minerals, and

ROCKS OF THE EARTH AND THEIR ORIGINS 13

RELATIVE ABUNDANCE OF THE PRINCIPAL ELEMENTS OF THE LITHOSPHERE 13

RELATIVE ABUNDANCE OF THE PRINCIPAL MINERALS OF THE LITHOSPHERE 14

RELATIVE ABUNDANCE OF THE PRINCIPAL ROCKS OF THE LITHOSPHERE 16

WATER (HYDROSPHERE) 18

SOILS AND CLAYS 18

COMPARISON OF LISTS OF MOST ABUNDANT ROCKS AND MINERALS WITH COMMERCIAL ROCKS AND MINERALS 18

THE ORIGIN OF COMMON ROCKS AND MINERALS 18 Igneous processes 19 Igneous after-effects 19 Weathering of igneous rocks and veins 20 Sedimentary processes 22 Weathering of sedimentary rocks 23 Consolidation, cementation, and other sub-surface alterations of rocks 24 Cementation 24 Dynamic and contact metamorphism 25

THE METAMORPHIC CYCLE AS AN AID IN STUDYING MINERAL DEPOSITS 27